Use of the NYPD's stop-and-frisk practice plummeted by more than 80 percent in the third quarter of this year from a year earlier, representing a continuation of the precipitous decline in use of the police tactic amid criticism and lawsuits, according to the department's latest data.

In the quarter ended Sept. 30, police performed 21,187 stop, question and frisks, compared with 105,988 in the same period of 2012, the data show. The statistics were provided Monday night to the City Council.

The data also showed that the racial and ethic breakdowns of those stopped by police remained largely unchanged over previous years: About 55 percent of the subjects stopped were black and 28 percent Hispanic, totaling about 84 percent among the two groups in the third quarter, compared with about 86 percent a year earlier.

Donna Lieberman, head of the New York Civil Liberties Union, said the lower stop-and-frisk numbers were good news. But Lieberman also said that the lower stop-and-frisk numbers, combined with continued drop in crime, showed the falsity of the City Hall argument that crime would increase if police did fewer stops.

Police officials have chalked up the decline in stop-and-frisk encounters, which has occurred for five of the last six quarters, to better training in the use of the tactic. But some law enforcement officials have privately said the drop has been caused by officers reacting to the August ruling by U.S. District Judge Shira Scheindlin finding that police had implemented it unconstitutionally against minorities. Her ruling has been stayed by a federal appeals court panel.

"Just as is the case with arrests, there is no predetermined or correct number of stops," NYPD spokesman John McCarthy said. "Ultimately, police officers make their decisions based on real-time observations from the field and those stops are based on reasonable suspicion."